JSFiddle - React, Tailwind, and code Playground

JavaScript

var courses =  [
	{ 
    name: 'JAVA',
    categoryid: '1',
  },
  {
    name: 'PHP',
    categoryid: '1',
  },
  {
    name: 'HR',
    categoryid: '2'
  }
]
                
var categories = [
	{
    catname: 'Information technology',
    categoryid: '1',

  },
  {
    catname: 'HR',
    categoryid: '2',

  },{
    catname: 'Sales',
    categoryid: '3'
  }
]

var result = [];
courses.map(function(course){
		var crs = categories.find(function(cat){return course.categoryid == cat.categoryid})
    
    if(	typeof crs !== "undefined" && result.indexOf(crs) < 0){
    	result.push(crs);
    }
    
})

console.log(result)